The present invention relates to wireless telecommunications in general, and more particularly to mobile terminal battery power conservation. Advanced wireless communication terminals, such as mobile phones, are nowadays equipped with a digital camera. Such a camera allows a user to capture images, to store the captured images on the memory of the mobile terminal, and to transmit these images to third parties. The captured images may be a “still” image (i.e. a single frame, like a conventional photograph) or may be a video clip (i.e. a series of frames captured in quick succession). The captured images may be transmitted in any suitable. However, the light is insufficient nighttime or in a dark environment, the image of the captured photograph will be blurred or unclear. Conventional cameras (including digital cameras) commonly include an additional light source or “flash” that is illuminated while an image is captured in low light conditions. However, wireless terminals are portable devices generally powered by rechargeable battery power sources. Conservation of wireless terminal battery power is desirable in order to allow the wireless terminal to maintain communications for as long as possible. Consequently, the types of light source generally incorporated into conventional film cameras and digital cameras are not the best choice for use in wireless terminals due to their size and power consumption. One approach to reduce the size and power consumption is to use a light emitting diode (LED) device which may be illuminated when an image is captured by a digital camera built into the wireless terminal in order to illuminate the subject of the captured image and thereby provide improved camera performance in low light conditions. Also other flash light techniques for wireless communication terminals have been developed. Moreover, conventional flash light techniques have improved in terms of size and power consumption.
Due to the size and power consumption requirements, the current capability of the batteries used in wireless terminal is quire restricted, and the battery voltage is relatively low, e.g. 2 to 4 volts. The problem is that flash uses relatively high power from the mobile terminal battery if e.g. white LED is used for light generation, and large power consumption pulse occurs during short period of time. The high instantaneous current needed by a flash may drop a supply voltage of the mobile phone low enough to make it inoperative. One approach could be to store the flash energy to a high-value capacitor, for example, but this would increase the price and size of a wireless terminal.